The name of the person who cleans the room will be written on the envelope along with a message: “Our caring room attendants enjoyed making your stay warm and comfortable. Please feel free to leave a gratuity to express your appreciation for their efforts.”

Shriver, who founded an organization called A Woman’s Nation that aims to empower women, says many travelers don’t realize tipping hotel room attendants is customary. “There’s a huge education of the traveler that needs to occur,” she said. “If you tell them, they ask, ‘How do I do that?'” She said envelopes make it easy for guests to leave cash for the right person in a secure way.

So how much should you leave? Marriott International CEO Arne Sorenson says $1 to $5 per night, depending on room rate, with more for a high-priced suite.

Sorenson noted that housekeepers “are less frequently tipped” than other hotel workers because they do an “invisible task.” In contrast, workers who carry bags, hail cabs and park cars tend to get tipped because they “make a personal connection” with guests, he said.

Rosario Rodriguez, who works as a housekeeper at Marriott’s Times Square hotel, says many guests don’t tip and welcomes the envelope campaign as “a good idea.”

Jessica Lynn Strosky of DuBois, Pennsylvania, who earns $7.75 an hour cleaning rooms at a hotel that’s not a Marriott, says only 1 in 15 or 20 guests leaves a tip. When they do, it’s a dollar or two; she’s lucky to get $20 a week in tips. “I’ve talked to lots of people who say they don’t know they are supposed to tip,” she said.

Unlike waitresses who earn less than minimum wage because tips are expected to raise their earnings, hotel housekeepers are paid minimum wage, and in expensive markets, substantially more. In Washington D.C., Sorenson said, Marriott housekeepers start in the mid-teens per hour.

Not everyone applauds the envelope concept. “It is not Marriott’s responsibility to remind customers to tip; it’s their responsibility to pay their workers enough so that tips aren’t necessary,” said author Barbara Ehrenreich, who tried working as a hotel maid for her 2001 book “Nickel and Dimed,” which chronicled her experiences in low-wage jobs.

But Scott Lazerson, 42, who lives in Sundance, Utah, said he “had no idea” tipping was customary until his wife told him on a recent trip to Orlando. He said he “feels stupid” for not knowing all these years, and added: “Yes, the hotel industry needs to do a campaign about it.”

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